<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <input type="text" name="" id="ipt">
    <script>
        /*
            onkeydown: 按下键盘
            onkeyup: 按下键盘抬起来

        */ 
        let ipt = document.querySelector('#ipt')

        ipt.onkeydown = ()=>{
            console.log('按下键盘');
        }

        ipt.onkeyup = ()=>{
            console.log('按下键盘抬起来了');
        }
    </script>
</body>
</html>